This proposal concerns the application of (Cycloheptatriene) Iron Tricarbonyl and (Cycloheptatrieneone) Iron Tricarbonyl to organic synthesis. Both of these have a number of attractive features which recommend their application to synthesis. Most importantly, the Fe(CO)3 fragment blocks one face of the coordinated ring, providing the opportunity for stereoselective carbon-carbon bond forming reactions. The proposal discusses methods for the simple elaboration of (C7H8)Fe(CO)3 and (C7H6O)Fe(CO)3. Building upon this methodology, several schemes for cyclization are considered. These include: side-chain nucleophilic attack on the coordinated diene, ring-centered enolate attack on the side chain and Lewis acid induced cyclization of a divinyl ketone. The methodology developed in this proposal will provide versatile intermediates for the stereocontrolled synthesis of conformationally labile natural products of interest to the health sciences.